The Sky This Week, 2013 January 22 - 29
The Moon & Jupiter, 2013 JAN 22, 03:49 UT
The Moon brightens the overnight skies this week as she wends her way from the stars of the Great Winter Circle to the rising glimmers of spring. The year’s first Full Moon falls on the 26th at 11:38 pm Eastern Standard Time. January’s Full Moon is popularly known as the Wolf Moon or Ice Moon. One popular Algonquian name that I particularly like is the "Frost in the Tepee" Moon. Luna may be found less than five degrees from the star Alhena, which marks the "foot" of Gemini Twin Castor, on the evening of the 24th. On the 25th she stands between the Gemini Twin Stars Castor and Pollux and the bright star Procyon, lead star in Canis Minor, the Little Dog. Look for the Moon to rise near the bright star Regulus, brightest star in Leo, the Lion, during the later evening of the 28th.
Bright moonlight will wash out all but the brightest stars this week, but fortunately her light won’t erase the lights of the winter constellations. Thanks to the presence of nine of the sky’s 25 brightest stars, these constellations are among the most easily recognizable star patterns. Chief among these is Orion, whose seven bright stars have been recognized as a striding figure of some notoriety in virtually every civilization’s sky lore. Since he straddles the Celestial Equator Orion is visible from every inhabited part of the globe. To the ancient Egyptians he was known as "Sahu", the heavenly embodiment of the spirit of Osiris, god of the dead. Funerary texts in Egyptian tombs refer to the deceased’s desire to be guided to the afterlife by Sahu, where they could enjoy beer, bread, and onions throughout eternity. To the ancient Irish, Norse, and Saxons he represented an "Armed King", while Medieval Arabs called him "Al-Jabbar", a name which means "The Giant". Even the Hobbits of Middle Earth had a name for him, "Menelvagor", which according to J.R.R. Tolkien translated to "The Swordsman of the Sky". Our "modern" interpretation of Orion comes to us from the Greeks and Romans, to whom Orion was a mighty hunter. He was the son of a mortal and the sea-king Neptune, described by Homer as "the tallest and most beautiful of men", and claimed dominion over all living creatures. Unfortunately his swagger didn’t make him many friends among the Greek immortals, and his boastful nature eventually inspired the wrath of Hera, who sent a lowly scorpion to dispatch the prideful Hunter. Orion and the scorpion were subsequently placed in the sky, but at opposite sides. Both constellations have bright reddish stars within their bounds, but the stars will never appear together at the same time! Orion is followed by his faithful dog Canis Major, marked by the dazzling star Sirius, which shines as a bright jewel in the dog’s collar. The Hunter and his dog seem to face the charge of Taurus, the Bull, whose face is marked by the V-shaped group of stars known as the Hyades with the bright reddish star Aldebaran glaring as the beast’s right eye.
You may notice another cluster of stars, the famous Pleiades, which seem to be perched on Taurus’ back. This group looks like a tiny version of the Big Dipper and is one of the most storied asterisms in the entire sky. They are riding on the Bull to escape the amorous overtures of Orion according to one legend, but as with Orion there are almost as many different stories about the Seven Sisters as there are for the Giant himself. Those of you who drive Subaru automobiles might like to brush up on Japanese sky lore next time you go out for a drive.
Perched between the Pleiades and the Hyades is the bright cheery glow of Jupiter. The giant planet is nearing the end of his retrograde loop for the current apparition and presents a wonderful view in binoculars of his perch between the two clusters. Look at him with a small telescope and his basic features become readily apparent. His disc displays its characteristic equatorial cloud belts while his four Galilean moons shuttle back and forth in their orbital paths, presenting a different view every night. Larger telescopes reveal more detail in his atmosphere. If you have a six-inch or larger telescope, watch the moon Io drag its shadow across the planet’s face on the evening of the 24th. You’ll also see an unusual configuration of the moons Ganymede and Callisto, and if the air is steady you should also be able to glimpse the Great Red Spot!
Golden Saturn is steadily creeping toward the evening sky. He now rises at around 1:00 am which places him close to the meridian as morning twilight begins to brighten the eastern horizon. The planet’s famous rings are visible in virtually any decent telescope, especially now that they are tilted almost 20 degrees to our line of sight. As with Jupiter, larger instruments will reveal more details, especially in the rings. Check him out if you feel like an invigorating morning activity!